Development of a Novel 18 F-Labeled Probe for PET Imaging of Estrogen Receptor β.

Estrogen receptor beta (ERβ) is an important ER subtype that plays crucial roles in many physiological and pathological disorders. Herein, we developed the probe [ 18 F]PVBO for in vivo ERβ targeted PET imaging and obtained promising results. The nonradioactive PVBO showed a 12.5-fold stronger binding affinity to ERβ than to ERα in vitro . In vitro assays revealed the specific uptake of [ 18 F]PVBO by DU145 cells. The uptake of [ 18 F]PVBO by DU145 xenografts increased during the 120 min dynamic scanning, with a maximum uptake of 2.80 ± 0.30% ID/g. Based on time activity curves (TACs), the injection of [ 18 F]PVBO with unlabeled PVBO or ERB-041 resulted in a significant signal reduction with the tumor/muscle (T/M) ratio <1 at 30, 60, 75, and 120 min post-injection ( p < 0.05). [ 18 F]PVBO demonstrates the feasibility of noninvasively imaging ERβ-positive tumors by small-animal PET and provides a new strategy for visualizing ERβ in vivo .